Mass Dispel no longer dispels magic effects that are normally undispellable. Cast time has been decreased to 0.5 seconds, down from 1.5 seconds for Discipline and Holy Priests.
Void Shift had its cooldown decreased to 5 minutes, down from 6 minutes for Discipline and Holy Priests. For Shadow Priests, cooldown has been increased to 10 minutes, up from 6 minutes, and the spell is no longer usable while in Arenas or Rated Battlegrounds.
Glyphs
Glyph of Mass Dispel has been redesigned and no longer reduces cast time. The glyph now enables Mass Dispel to dispel magic effects that are normally undispellable.
Discipline
Atonement now heals nearby friendly targets for 80% of the damage dealt, down from 100%.